package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.util.Collections;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private ISeckillVoucherService seckillVoucherService;
    @Autowired
    private RedisIdWorker redisIdWorker;//注入ID生成器

    @Autowired
    StringRedisTemplate stringRedisTemplate;

    @Autowired
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
   private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024*1024);
   private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

   @PostConstruct
   private void init() {
       SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
   }
   private class VoucherOrderHandler implements Runnable {

       @Override
       public void run() {
           while (true) {
               try {
                   VoucherOrder voucherOrder = orderTasks.take();
                   handleVoucherOrder(voucherOrder);
               }catch (Exception e) {
                   log.error("处理订单异常",e);
               }


           }

       }
   }

   private void handleVoucherOrder(VoucherOrder voucherOrder) {
       //获取用户
       Long userId=voucherOrder.getUserId();
       //创建锁对象
       RLock lock=redissonClient.getLock("lock:order:" + userId);
       //获取锁
       boolean isLock=lock.tryLock();
       //判断是否获取锁成功
       if(!isLock){
           log.error("不允许重复下单");
           return;
       }
       try{
           proxy.createVoucherOrder(voucherOrder);
       }finally {
           lock.unlock();
       }


   }

   private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //1，执行lua脚本
        Long result=stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()

        );
        //2，判断结果是否为0
        int r=result.intValue();
        if(r!=0){
            //2.1不为0，代表没有购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }




        //2.2为0，有购买资格，把下单信息保存到阻塞队列中
        VoucherOrder voucherOrder=new VoucherOrder();
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setUserId(userId);
        long orderId=redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();


        //返回订单id
        return Result.ok(orderId);
    }


   /* @Override
    public Result seckillVoucher(Long voucherId) {
        //查询优惠券
        SeckillVoucher seckillVoucher=seckillVoucherService.getById(voucherId);

        //判断秒杀是否开始或结束
        if(seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀尚未开始");
        }
        if(seckillVoucher.getEndTime().isBefore(LocalDateTime.now())){
            return  Result.fail("秒杀已经结束");

        }

        //判断库存是否充足
        if(seckillVoucher.getStock()<1){
            return Result.fail("库存不足");

        }
        Long userId=UserHolder.getUser().getId();
        //一人一单

        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock=lock.tryLock();
        if(!isLock){
            //获取锁失败，返回错误或重试
            return Result.fail("不允许重复下单");
        }

            try {
                IVoucherOrderService proxy=(IVoucherOrderService) AopContext.currentProxy();
                return proxy.createVoucherOrder(voucherId);
            }finally {
                //释放锁
                lock.unlock();
            }
            //返回订单号



    }
    */

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
            Long userId=voucherOrder.getUserId();

            int count=query().eq("user_id",userId).eq("voucher_id", voucherOrder).count();
            if(count>0){
                log.error("该用户已经购买过");
                return;
            }
            //扣除库存
            boolean success= seckillVoucherService.update()
                    .setSql("stock=stock-1")
                    .eq("voucher_id", voucherOrder)
                    .gt("stock",0)
                    .update();
            if(!success){
                log.error("库存不足");
                return;
            }
            //创建订单

            save(voucherOrder);




    }
}
